With Unity's InputSystem is there a way to discriminate between players when using c# events?

I am experimenting with Unity and have created a multi-player local coop environment. I have a Player Input Manger create a new player whenever a new device connects. These players have a Player Input component that is set to use c# events. Then I have some code that listen for the events and logs to the console. I want to be able to distinguish between players, but at the moment events get fired for every input on every device.

I have watched countless tutorials on the Input System, but local multiplayer never seemns to be addressed. All the solutions I can think off seem nasty. I can get it working with send, broadcast and unity's events, but I would like to know how to achive it with c# events.

I don't think you can through the event system, no.

However, if you use the Input Manager directly (i.e. Input.GetButtonDown()), then you can go into your project settings and set up the buttons and axes to be gamepad specific.

Essentially, what you need to do is duplicate all of the buttons and axes in the Project Settings Input Manager for however many players you want to support, and then go through them and set the Joystick index to a fixed custom value.

Then, instead of having, for example, a "Jump" button, you'll have "Jump 1" through "Jump 4", each unique to its own gamepad.

See the last entry in the Virtual Axes table for more info:
https://docs.unity3d.com/Manual/class-InputManager.html